Central effects of paraoxon on haemodynamics in the cat

Summary Application of paraoxon into the left vertebral artery (8–80 g) or both the left and right vertebral artery (4–8 g) of the anaesthetized cat evoked dose-dependent depressor effects, whereas heart rate was not influenced significantly. Also after systemic administration of paraoxon (150–825 g·kg^–1), while peripheral muscarinic receptors were blocked, depressor effects were still observed. Dose-response curves for the depressor response to paraoxon were established. Infusion of low doses of dexetimide via the vertebral artery prevented the hypotensive action of paraoxon. The distribution of this antimuscarinic drug in the brain was investigated. The depressor effect of paraoxon can be attributed to both a decrease in peripheral resistance and cardiac output. Decerebration and midcollicular transection were carried out in order to elucidate the site and mechanism of action. The depressor effect of paraoxon seems to be mediated by a central mechanism of action located within the lower brain stem.It is concluded that stimulation of muscarinic receptors in the pontomedullary region gives rise to the observed changes in haemodynamic parameters. Muscarinic receptors in the hypothalamus seem to be of minor importance for the hypotensive action of paraoxon.     

Clinical significance of retrograde flow in the vertebral artery

Although retrograde vertebral artery flow was described over 100 years ago, its relationship to symptoms remains unclear. We documented 43 patients who were found by duplex scanning to have reverse flow in the vertebral artery. Of this group, seven patients (16%) were found to have symptoms described as typical for the subclavian steal syndrome. Nearly one-third were asymptomatic. Of the remaining patients, 13 (30%) presented with nonhemispheric symptoms while nine (21%) had hemispheric symptoms. Nine patients had to and fro flow in the vertebral artery. This variant was not found in subclavian steal patients but correlated with nonhemispheric symptoms. During follow-up (mean: 19 months) none of the asymptomatic patients became symptomatic, and there were no strokes or stroke-related deaths. Surgical procedures which restored antegrade vertebral artery flow did not necessarily improve symptoms of posterior circulation ischemia. In some patients improvement in posterior circulation symptoms was noted following carotid endarterectomy. It is concluded that retrograde flow in the vertebral artery is, per se, a benign entity. Accurate selection of surgical candidates remains imprecise. It will require not only identification of vertebrobasilar disease but as yet undefined tests to assure symptoms are due to these stenoses.     

Unusual fractures and dislocations of the axis vertebra

Seven percent of 400 patients with cervical spine fractures and/or dislocations had unusual lesions of the axis. The authors have analyzed axis injuries by review of radiographs and clinical data and have derived a classification of traumatic conditions. Uncommon traumatic axis abnormalities are discussed with reference to incidence, causes, clinical findings, mechanism of injury, and roentgen characteristics.Picker Scholar, James Picker Foundation     

Augmentation with sulpiride for a schizophrenic patient partially responsive to clozapine

OBJECTIVE: Schizophrenic patients who are only partially responsive to clozapine pose a therapeutic challenge. In these circumstances some clinicians would consider adding in a second antipsychotic. We present a case report and review evidence for the efficacy of such augmentation strategies. METHOD: Single case report and literature review. RESULTS: The total number of patients in studies and case reports of combining clozapine with other antipsychotics is small. There has been only one randomized controlled trial. This found the addition of sulpiride to clozapine resulted in clinical improvement in some patients. CONCLUSION: Further randomized controlled studies of augmentation of clozapine therapy are needed to provide scientific justification for this clinical practice.     

应用内置钛镍记忆合金牵张器在下颌骨牵张成骨的初步研究

目的　探索利用钛镍记忆合金牵张成骨增高下颌牙槽嵴和修复下颌骨节段性缺损的可行性。方法　 2 0只成年杂种犬分为 5组 ,Ⅰ组和Ⅱ组进行牵引成骨增高下颌骨牙槽嵴 ,Ⅲ组和Ⅳ组进行牵引成骨修复下颌骨缺损 ,Ⅴ组作为对照。牵引成骨用自行设计制作的内置型钛镍合金牵张器 ,在牵张手术前及术后 1、5、13周拍X线片 ,分别在牵张完成后 1、3个月处死动物 ,进行组织学研究。结果　钛镍牵张器显示了良好的组织相容性 ,自动完成牵引骨形成 ,牵张器安置完成后骨块即开始移动 ,X线片可见牵张完成后 1个月牵张区骨密度增高 ,有新骨生成 ;3个月时新生骨密度与周围骨接近 ,有效地增加了牙槽嵴的高度和初步修复了下颌骨的节段性缺损。组织学观察可见牵张区新骨形成良好。结论　内置自加载钛镍记忆合金牵张器自动牵引成骨是一种具有良好应用前景的简便实用的牵引成骨技术。     

Augmentation of Shoulder Contour Using a Calf Implant

Sprengel deformity is a rare orthopedic condition that is associated with functional and cosmetic impairment. Results of orthopedic procedures are usually inconsistent and cosmetic results are far from satisfactory in these patients. A silicone-gel-filled calf prosthesis was used to correct the shoulder contour in a patient with Sprengel deformity. Cosmetically the deformity can be restored by using a calf implant for patients in whom orthopedic procedures are not likely to yield a satisfactory outcome.     

Reference Data of Vertebral Morphometry by X-ray Absorptiometry (MXA) in Argentine Women

Anterior, middle, and posterior heights and A/P and M/P ratios were determined from T5 to L4 in 111 normal Caucasian Argentine women from 20 to 70 years of age using dual energy X-ray absorptiometry (DXA) densitometry (Expert XL). Scanning time was less than 1 minute and the semiautomatic analysis requires ∼5 minutes. The precision error for the measurements ranged from 2.2% to 4.6%. The absolute precision error for heights was 0.6 mm. The vertebral bodies tended to be significantly larger in younger women than older women, especially for anterior and middle heights and the A/P and M/P ratios of the mid-thoracic vertebrae (T6–T10). There were no significant differences between pre- and postmenopausal women in the lumbar vertebral heights. It does not appear that this was a cohort effect because stature was identical in both age groups, and there was no age difference in posterior height. The Expert-XL software normalized the vertebral height based on the average height of the L2-L4 segment in order to minimize the influence of interindividual variation of body size. The average Z-scores for vertebral heights and ratios provided by the software were close to zero indicating that the normalization procedure appropriately corrected for smaller stature in Argentine women. Consequently, the reference values for morphometry X-ray absorptiometry (MXA) were appropriate for our population. In summary, we found that (1) in ``normal' women the anterior heights of the thoracic vertebrae (and therefore the A/P ratio) were higher in premenopausal than in postmenopausal women; and (2) the normalization approach corrected for differences of vertebral height and allowed utilization of the manufacturers software in our population. Received: 28 June 1999 / Accepted: 2 November 1999     

The relationship between phalangeal bone density and vertebral deformities

Radiographic absorptiometry (RA) of the phalanges is a convenient and reliable technique for measuring bone mineral density (BMD). It needs only a radiograph of the hand, which can be sent for evaluation to a central facility, whereas other techniques require specialized equipment. We assessed the relationship between RA measurements and the presence of vertebral deformities in a population-based cohort of postmenopausal women, and to compare the results with simultaneously obtained BMD of the hip by dual-energy X-ray absorptiometry (DXA). A total of 389 women aged 55–84 (mean age 67.2 years, SD 8.7) were randomly selected from a large general practice. RA, DXA of the hip, and vertebral deformities in the lateral spine X-rays by vertebral morphometry were assessed. Thirty-eight women (9.8%) had severe (grade II) vertebral deformities, and their BMD at the phalanges and femoral neck was significantly lower than that of women without severe vertebral deformities. Odds ratios for the presence of severe vertebral deformities of 1.5 (95% CI: 1.1–2.1) for RA and 1.3 (95% CI: 0.9–1.9) for DXA, together with similar receiver operating characteristics curves, were found using age-adjusted logistic regression. Phalangeal BMD is related to vertebral deformities at least as closely as BMD of the femoral neck BMD. RA may therefore help to evaluate fracture risk, especially if no DXA equipment is available. Received: 21 July 1998 / Accepted: 1 July 1999     

脊椎血管瘤手术后复发放射治疗疗效观察(附6例报告)

目的 探讨脊椎血管瘤手术后复发放射治疗疗效和适宜剂量。方法 1968—1992年间共收治手术后复发的有症状的脊椎血管瘤6例，中位年龄28岁。病灶在胸椎5例，腰椎1例。4例有病灶局部疼痛合并不完全性截瘫，2例为局部疼痛合并下肢麻木无力。采用^60Co和8MV—X线照射治疗，总剂量范围30-60Gy，平均40Gy。结果 所有接受放疗的患均获得良好的远期效果，4例不完全截瘫患中3例基本恢复，1例完全恢复，另外2例原有的下肢麻木症状消失，但影像学检查均无明显改变。结论 放射治疗对手术后复发的脊椎血管瘤是安全有效的，剂量以36—40Gy为宜。但放射治疗起效比较慢，且影像学改变不明显，所以应以远期症状改善率作为评价放射治疗效果的标准。     

Stomach versus sigmoid colon in children undergoing major reconstruction of the lower urinary tract

A review of 50 patients who underwent intestinocystoplasty (ICP) or gastrocystoplasty (GCP) replacement at our department during an 8-year period is presented. The most common diagnoses were neurogenic bladder and bladder exstrophy. A total of 48 patients underwent augmentation cystoplasty and 2 had total bladder replacement. Mean follow-up time was 42 months. The clinical and metabolic aspects of the two types of ICP are reported. Hyperchloremic acidosis requiring therapy was not encountered, although mild degrees were seen after sigmoid augmentation in 36% of patients. A dysuria-hematuria syndrome (DHS) was seen in 50% of the patients who underwent GCP. Operative mortality rate was nil. Significant surgical complications occurred in 36% of the patients. The overall success rate for ICP and GCP in this series was 79.15%. ICP gives effective results when used to increase the compliance of the lower urinary tract, but problems related to electrolyte absorption, stones, and mucus production are often encountered. In GCP electrolyte absorption is practically eliminated, so that this technique can be used in patients with renal damage. In addition, patients with a normal bladder plate (bladder exstrophy) can achieve normal voiding with time. The authors believe that patients must be made aware of the possibility of DHS and that this syndrome needs further investigation.